JP2005336042A - Gas generating agent composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas generating agent composition having a low combustion temperature and a high rate of burning. <P>SOLUTION: The gas generating agent composition comprises a fuel and an oxidizing agent, and, if needed, a binder and an additive agent. The fuel contains one kind or two or more kinds selected from among glycine or its derivatives. The combination of the fuel of glycine, the oxidizing agent of a basic copper nitrate, and the binder of carboxymethyl cellulose or its salt is preferable. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a gas generant composition used for a gas generator for an air bag.

  Gas generators used in air bag gas generators generally consist of fuel, oxidant, binder, and various additives. Recently, gas generation using azide compounds that generate harmful gases as fuel. Instead of the agent, a safer gas generating agent using a non-azide compound as a fuel is used.

  In order to ensure the safety of passengers by inflating the airbag as designed in the event of a car collision, in addition to not generating harmful gas, The following three requirements are required to be satisfied.

(A) Lower the combustion temperature to suppress thermal damage to the airbag. (B) Reduce the amount of combustion residue to prevent the combustion residue from entering the airbag and damaging the airbag. (C) In order to inflate and deploy the airbag within a predetermined time (usually about several tens of milliseconds), the combustion rate of the gas generating agent is high. Patent Document 1 discloses a low-residue gas generating agent composition, A composition comprising 5-nitrouracil or the like and basic copper nitrate is disclosed, and Patent Document 2 discloses a composition comprising a binder / fuel / oxidant as a gas generant composition having a combustion temperature of 2100 K ° or less. ing.
US2003 / 094225A1 US2003 / 145921A1

  In the requirement (a), in order to suitably maintain the combustibility of the gas generating agent which is an explosive, in order to suppress thermal damage of the airbag when the combustion temperature is increased, a large amount of coolant is contained in the gas generator. Must be incorporated.

  In requirement (b), when the amount of combustion residue is large, it is necessary to incorporate a large amount of coolant in the gas generator in the same manner as described above in order to prevent the combustion residue from being released into the airbag.

  In requirement (c), if the combustion rate is too low, the airbag may not be inflated within a predetermined time.

  However, if the combustion temperature of the gas generating agent is decreased to satisfy the requirement (a), the combustion rate is also decreased, and thus the requirement (c) cannot be satisfied. Furthermore, even if the requirement (a) is satisfied, the coolant cannot be reduced unless the requirement (b) is satisfied.

  This invention makes it a subject to provide the gas generating composition which can satisfy | fill all requirements (a)-(c) while suppressing generation | occurrence | production of the noxious gas at the time of combustion.

  As a means for solving the problems, the present invention contains a fuel and an oxidant, and optionally contains a binder and an additive. The fuel contains one or more selected from glycine or a derivative thereof. A gas generant composition is provided.

  The gas generant composition of the present invention can suppress the generation of harmful gases during combustion. Furthermore, since the gas generant composition of the present invention can satisfy all of the above requirements (a) to (c), the weight of the gas generator itself can be reduced by reducing the amount of coolant incorporated in the gas generant. In addition, since the airbag is prevented from being damaged, safety during operation can be improved.

  The fuel used in the gas generant composition of the present invention contains one or more selected from glycine or a derivative thereof, and if necessary, a fuel component other than glycine or a derivative thereof may be used in combination. it can.

  Examples of the glycine derivative include glycylglycine, anhydrous glycine, glycine anhydride, glycine metal salt, glycine coordinated metal complex salt, alanine, iminodiacetic acid, creatine, or creatinine.

  When glycine or a derivative thereof and another fuel component are used in combination as a fuel, the content ratio of glycine or a derivative thereof in the fuel is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 80% by mass. %, But only glycine or a derivative thereof (however, in this case, it is allowed to contain a very small amount of other fuel components as impurities or not to affect the effect at all). Particularly preferred.

  Other fuel components include tetrazole derivatives such as 5-aminotetrazole, bitetazole derivatives such as bitetrazole diammonium salt, triazole derivatives such as 4-aminotriazole, guanidine derivatives such as dicyandiamide, nitroguanidine and guanidine nitrate, trihydra Examples thereof include one or more nitrogen-containing compounds selected from triazine derivatives such as dinotriazine, oxamide, ammonium oxalate, azodicarbonamide, hydrazodicarbonamide, and the like.

  The oxidizing agent used in the gas generant composition of the present invention is preferably an inorganic oxide, and as the inorganic oxide, basic copper nitrate, sodium nitrate, potassium nitrate, strontium nitrate, sodium perchlorate, potassium perchlorate, perchlorine The 1 type (s) or 2 or more types chosen from acid strontium can be mentioned.

  In the gas generant composition of the present invention, a binder can be blended as necessary. As the binder, carboxymethylcellulose (CMC), carboxymethylcellulose sodium salt (CMCNa), carboxymethylcellulose potassium salt, carboxymethylcellulose ammonium salt, cellulose acetate, cellulose acetate butyrate (CAB), methylcellulose (MC), ethylcellulose (EC), hydroxy Ethyl cellulose (HEC), ethyl hydroxyethyl cellulose (EHEC), hydroxypropyl cellulose (HPC), carboxymethyl ethyl cellulose (CMEC), microcrystalline cellulose, polyacrylamide, polyacrylamide amination, polyacryl hydrazide, acrylamide / acrylic acid metal salt Copolymer, Copolymer of polyacrylamide / polyacrylic acid ester compound Polyvinyl alcohol, acrylic rubber, may be mentioned guar gum, starch, one or more kinds selected from silicone.

  Among these, considering the adhesive performance, price, ignitability and the like of the binder, a water-soluble cellulose compound is preferable, and carboxymethyl cellulose sodium salt (CMCNa) is particularly preferable.

  In the gas generant composition of the present invention, various additives blended with known gas generants can be blended as necessary. Additives include metal oxides such as copper oxide, iron oxide, zinc oxide, cobalt oxide, manganese oxide, molybdenum oxide, nickel oxide, bismuth oxide, silica, and alumina; cobalt carbonate, calcium carbonate, basic zinc carbonate, base Metal carbonates such as basic copper carbonate or basic metal carbonates; complex compounds of metal oxides or hydroxides such as acid clay, kaolin, talc, bentonite, diatomaceous earth, hydrotalcite; sodium silicate, mycamolybdic acid Metal salts such as salts, cobalt molybdate and ammonium molybdate; one or more selected from molybdenum disulfide, calcium stearate, silicon nitride and silicon carbide can be used.

  The content ratio of each component in the gas generant composition of the present invention can be selected from the following ranges.

  The fuel is preferably 1 to 50% by mass, more preferably 5 to 40% by mass, and still more preferably 10 to 30% by mass in the gas generant composition.

  The oxidizing agent is preferably 20 to 99% by mass, more preferably 40 to 95% by mass, and still more preferably 60 to 90% by mass in the gas generant composition.

  When the binder is blended, it is preferably 0.1 to 30% by mass, more preferably 0.5 to 20% by mass, and further preferably 3 to 10% by mass in the gas generant composition.

  In addition, when adding an additive as needed, although it changes with kinds of additive, 0.01-20 mass parts can be mix | blended with respect to a total of 100 mass parts of a fuel, an oxidizing agent, and a binder.

  The gas generating composition of the present invention is particularly preferably a combination of glycine as a fuel, basic copper nitrate as an oxidizing agent, and carboxymethyl cellulose or a salt thereof (particularly CMCNa) in order to solve the problems of the present invention.

  The gas generant composition of the present invention can be formed into a desired molded body such as a single-hole cylindrical shape, a porous cylindrical shape, or a pellet shape. These molded products are prepared by adding water or an organic solvent to the gas generating agent, mixing and extruding (single-hole cylindrical or porous cylindrical molded body) or compression molding using a tableting machine (pellet). In addition, the method described in JP-A-2001-320991 can also be applied.

  The gas generating composition of the present invention includes, for example, an airbag inflator (gas generator) for driver seats of various vehicles, an airbag inflator for passenger seats, an inflator for side airbags, an inflator for inflatable curtains, and a knee bolster. The present invention can be applied to inflators, inflators for inflatable seat belts, inflators for tubular systems, and inflators for pretensioners.

  The gas generant composition of the present invention can be used as a gas generant composition for an inflator (gas generator), and an enhancer agent (or an agent for transmitting energy of a detonator or a squib to the gas generant composition (or It can also be used as an igniter called a booster.

  The measuring method in an Example and a comparative example is shown. In the following, “part” means “part by mass”.

(1) The composition of Preparation Examples and Comparative Examples of cylindrical strands (as mixed powder. Table 1 for molding.) Powder was filled in a die side of a predetermined mold, hydraulic than punch-side end surface After being compressed and held with a pump at a pressure of 14.7 MPa for 5 seconds, it was taken out and formed into a cylindrical strand having an outer diameter of 9.55 mm and a length of 12.70 mm. After applying an epoxy resin chemical reaction type adhesive ("Bond Quick 30" manufactured by Konishi Co., Ltd.) to the side surface of this cylindrical strand, it is thermally cured at 110 ° C for 16 hours, and does not ignite from the side surface. Samples that were ignited and combusted (single-surface moving combustion) were used as samples.

(2) Measuring method of burning rate The cylindrical strand used as a sample was installed in a SUS sealed bomb having an internal volume of 1 L, and pressure was stabilized to 7 MPa while completely replacing the inside of the bomb with nitrogen. After that, a predetermined current was passed through the nichrome wire brought into contact with the end face of the strand, and ignition and combustion were performed by the fusing energy. The time-dependent pressure behavior in the bomb is confirmed on the chart of the recorder, the elapsed time from the start of combustion to the pressure rise peak is confirmed from the scale on the chart, and the strand length before combustion is divided by this elapsed time. The calculated value was taken as the burning rate.

(3) Gas concentration measurement method Cylindrical strand (mass 2.00 g) as a sample was placed in a 1 L SUS sealed bomb and pressurized to 7 MPa while completely replacing the inside of the bomb with nitrogen. Stabilized. After that, a predetermined current was passed through the nichrome wire brought into contact with the end face of the strand, and ignition and combustion were performed by the fusing energy. After waiting 60 seconds and the gas in the bomb becomes uniform, sampling is performed by connecting the opening part of the tedlar bag with a predetermined stopper to the bomb gas discharge part, and introducing the combustion gas in the bomb. ) Manufactured by GV-100S, using a gas-tech gas detector tube (for NO ₂ and NO detection: No. 10, for NH ₃ detection: No. 3L, for CO detection: No. 1L), NO ₂ , NO, NH ₃ and CO concentrations were measured.

(4) Mass of recovered residue After completion of the above “(3) Gas concentration measurement method” test, the internal state of the bomb was visually observed and the internal residue was recovered and dried at 110 ° C. for 16 hours. The mass of was measured.

Example 1
The composition of the present invention was obtained by rubbing 14.8 parts of glycine and 85.2 parts of basic copper nitrate twice through a SUS sieve having a mesh size of 300 μm and mixing and mixing. The measurement results are shown in Table 1.

Example 2
21.69 parts of glycine, 73.31 parts of basic copper nitrate, and 5 parts of CMCNa were rubbed twice through a 300 μm mesh SUS sieve to prepare a mixed powder. 20 parts of ion-exchanged water was added to 100 parts of this mixed powder and mixed well, followed by drying at 110 ° C. for 1 hour to obtain the composition of the present invention. The measurement results are shown in Table 1.

Comparative Examples 1 and 2
Using the components shown in Table 1, compositions were obtained in the same manner as in Examples 1 and 2, respectively. The measurement results are shown in Table 1.

Examples 3-7
An example using the components shown in Table 1 and not using CMCNa was the same as in Example 1, and an example using CMCNa was the same as in Example 2 to obtain the composition of the present invention. The measurement results are shown in Table 1.

  As described above, in the compositions of the examples, the amount of harmful gas generated during combustion was suppressed. Further, after the completion of “(3) Gas concentration measurement test”, the internal state of the bomb was visually observed, and the following state was obtained.

  In Example 1, only one substantially cylindrical metal copper lump was confirmed as a residue formed with very good slag, and in Example 2 only one substantially cylindrical metal copper lump was confirmed. Further, in Examples 4 and 6, only one columnar metal copper mass was confirmed as a residue with very good slag formation.

  In Comparative Example 1, residues scattered as countless fine metallic copper were confirmed. Such scattering of fine metal copper may damage the airbag when the airbag is inflated and deployed. In the comparative example 2, the residue scattered as several granular metal copper around 1 mm was confirmed. Such scattering of the granular metal copper may damage the airbag when the airbag is inflated and deployed.

Thus, the compositions of the examples had high combustion gas safety, good slag forming ability, and a low combustion temperature, but the combustion rate was sufficiently high.

Claims (5)

  A gas generant composition containing a fuel and an oxidant, optionally containing a binder and an additive, and containing one or more selected from glycine or a derivative thereof as the fuel.   The gas generant composition according to claim 1 or 2, wherein the glycine derivative is glycylglycine, anhydrous glycine, glycine anhydride, glycine metal salt, glycine coordinated metal complex salt, alanine, iminodiacetic acid, creatine or creatinine.   The oxidizing agent is one or more inorganic oxides selected from basic copper nitrate, sodium nitrate, potassium nitrate, strontium nitrate, sodium perchlorate, potassium perchlorate, and strontium perchlorate. 3. The gas generant composition according to 2.   The gas generant composition according to any one of claims 1 to 3, wherein the binder is a water-soluble cellulose compound. The gas generating composition according to any one of claims 1 to 4, wherein the fuel is glycine, the oxidizing agent is basic copper nitrate, and the binder is carboxymethyl cellulose or a salt thereof.